Depression linked to lack of love/sex? What can I do about it while not having love/sex?

This seems to be a common theme in my life: Everything is going well, I am happy, then all of a sudden I become depressed. This seems to correlate with about a two to three month period after my last date with a man. I am quite happy with waiting for the right guy to come around, so messing around is out of the question (and depresses me as well). How can I heal myself for good naturally without a man? How can I be in love with myself? Thanks for any advice.
Note: I have a very healthy diet, work full time, am involved in my community, and am an athlete. Tweet